<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            padding: 0px;
            margin: 0px;
        }
        body {
            display: flex;
            justify-content: center;
        }
        .wrap {
            width: 80%;
            height: 2000px;
            background: rgba(233, 240, 99, 0.734);
        }
        .tool {
            height: 200px;
            width: 50px;
            background: #ff6700;
            position: fixed;
            /* top: 0; */
            left: 0;
            /* right: 85px; */
            bottom: 0px;
        }
    </style>
</head>
<body>
    <div class="wrap">
        <h1>固定定位</h1>
        <div class="tool"></div>
    </div>
</body>
</html>